I don't know about the amino acids, but you may have taken too much niacin (B3):

"Another feature of niacin is that it dilates blood vessels and creates a sensation of warmth, called a "niacin flush." This is often accompanied with a blushing of the skin. It is this "flush" or sensation of heat that indicates a temporary saturation of niacin, and that is our topic here.

When you flush, you can literally see and feel that you've taken enough niacin. The idea is to initially take just enough niacin to have a slight flush. This means a pinkness about the cheeks, ears, neck, forearms and perhaps elsewhere. A slight niacin flush should end in about ten minutes or so. If you take too much niacin, the flush may be more pronounced and longer lasting. If you flush beet red for half an hour and feel weird, well, you took too much. And large doses of niacin on an empty stomach is certain to cause profound flushing."